If you are on a release of Trisquel 9, Linux Mint 19.x or Ubuntu 18.04-Ubuntu 19.10 the scanner is not yet supported out of the box. See our directions on how to update SANE and related scanner drivers as they pertain to this scanner.
If you are on Ubuntu 20.04, Linux Mint 20, or any distribution based on Ubuntu 20.04 you may need to remove a package for the scanner to work properly. Despite being detected you will get an error when attempting to scan otherwise. A bug report has been filed with Ubuntu.
Open a terminal and run the following command:
sudo apt remove ippusbxd
scanimage
Or watch the complete setup video: